Dividends and Distribution Payable (Details) - $ / shares	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Dividends Payable [Line Items]
Dividends Payable, Amount Per Share	$ 1.845	$ 1.740	$ 1.640
Dividend Declared, Ordinary Income [Member]
Dividends Payable [Line Items]
Dividends Payable, Amount Per Share	1.519	1.398	1.372
Dividend Declared, Return of Capital [Member]
Dividends Payable [Line Items]
Dividends Payable, Amount Per Share	$ 0.326	$ 0.342	$ 0.268